Refraction and Critical Angle Worksheet

You look at your feet in water and they appear to be in a different spot. This is due to:

• reflection

• incidence

• total internal reflection

• refraction

When a ray of light enters a second medium at 90°, the incident angle is called the ____________ angle.

• incident

• critical

• reflected

• refracted

When a ray of light goes from one type of material into another at an angle of 0° to the normal, at what angle will the light pass through the second material?

• 90°

• 45°

• 22.5°

• 0°

What happens when you reach the critical angle for a substance?

• The light will be reflected at the same angle as the critical angle

• The light will bend towards the normal

• The light will be totally internally reflected

• The light will bend away from the normal

If you calculate the angle of refraction and get an ERROR, what does that mean?

• You’re past the critical angle so total internal reflection occurs

• You’re below the critical angle so total internal reflection occurs

• You’re below the critical angle so all of the light is reflected

• You’re below the critical angle so all of the light is reflected

In which of the following instances would there be a critical angle?

• air to water

• water to diamond

• ruby to glycerine

As the index of refraction (n) increases, the speed of light in that material:

• increases

• decreases

• remains the same

• doubles

As the index of refraction (n) increases, what happens to the angle of refraction in that material?

• Bends away from the normal

• bends towards the normal

• doesn’t bend at all

As the index of refraction (n) increases, what happens to the critical angle for that material?

• increases

• decreases

• stays the same

For a convex/converging lens, where is the primary focus found?

• on the same side

• opposite side of the lens as the image